A conventional tool for fixedly holding two workpieces together is usually a telescopic screw, which includes a sleeve, a screw and a spring. To use the conventional telescopic screw, first fix the sleeve to a workpiece, and then extend the screw through the workpiece to lock to another workpiece, so that the two workpieces are held to each other. However, in the conventional telescopic screw, the screw tends to shake relative to the sleeve and could not be easily aligned with the fastening hole formed on the other workpiece. In addition, the screw for the conventional telescopic screw has a relatively small head, preventing the screw from being easily pushed downward or pulled upward in the process of aligning the screw with the fastening hole.
It is therefore tried by the inventor to develop an improved fastening device that includes a reciprocation actuator to prevent a fastening member of the fastening device from shaking, so that a fastening unit of the fastening member can be conveniently moved in a reciprocating motion inside and outside a locating seat of the fastening device and be accurately fastened to a workpiece.